Dry diatomaceous earth feeder



Oct. 19, 1965 A. KROMHOUT ETAL 3,212,672

DRY DIATOMACEOUS EARTH FEEDER 2 Sheets-Sheet 1 Filed Aug. zo, 1962 Oct.19, 1965 A. KROMHOUT ETAL 3,212,672

DRY DIATOMACEOUS EARTH FEEDER 2 Sheets-Sheet 2 Filed Aug. 20, 1962United States Patent 3,212,672 DRY DATGMACEUUS EARTH FEEDER AndrewKromhout, deceased, late of Elgin, Ill., by Sarah M. Kromhout,executrix, and De Wayne Wessel, Elgin,

Ill., assignors, by rnesne assignments, to Elgin Softener Inc., Elgin,Ill., a corporation of Illinois Filed Aug. 20, 1962, Ser. No. 227,620Claims. (Cl. Z22-56) This invention relates to mechanical feedingdevices and is more particularly concerned with a dry diatomaceous earthfeeder, suitable for use in swimming pool filtration apparatus, forexample.

The principal object of our invention is to provide a feeder of the kindmentioned utilizing a chain attached to a radius arm on the upper end ofa vertical shaft and rotatable in the center of an upright generallycylindrical container having a funnel-shaped lower end portion fordelivery of the fine granular material in calibrated amounts through acentrally located cylindrical throat or spout provided in the lower endof the funnel through which a vertical shaft extends downwardly from thecenter of the hopper, a propeller in the form of an elongated verticalU-bolt fastened to the shaft operating in the throat to eliminate anypossibility of material packing therein, and the lower end portion ofthe chain, which is preferably of smaller size, being connected with thepropeller so as to form with the shaft an auger by wrapping around theshaft so long as the hopper contains a large amount of the material tobe fed, whereby to keep a clear passage down through the center of thematerial and eliminate any possibility of packing and plugging at theentrance to the throat, the heavier chain forming the major portion ofthe length of the chain employed tending normally to hang verticallydownwardly from the radius arm and sweep first on top of the bed ofmaterial to loosen some material and spill it down through the centralpassage until nearly all of the material is used up, this chain latersweeping the inside walls of the hopper as well as the roundedfunnelshaped bottom portion thereof to remove the last `of the materialfrom the sides and bottom.

In accordance with a further object of our invention, the shaft has acircular plate turning with it relative to the spout that forms thedischarge end of the hopper and defining a delivery slot annularlythereof by reason of its closely spaced relationship to the lower end ofa collar that is disposed in telescoping relation to the aforesaidspout, the plate and collar being relatively adjustable axially to varythe Width of the slot and Ithereby the rate of feeding of the materialas desired. This enables very fine adjustment of feed, as required forswimming pool filtration apparatus.

A further object is to provide in one assembly with the dry earth feedera combination float box and mixing chamber into which water is deliveredto maintain a predetermined level in the mixing chamber where a slurryis formed by a mixture of the diatomaceous earth and water and iscontinuously pumped to a filter to maintain a predetermined thickness ofthe earth therein to insure eiiicient filtering action. The amount ofdiatomaceous earth to be fed is, of course, dependent on the amount ofwater from the pool circulated through the lter per hour, a normal feedbeing .05 to .O8 lb. of diatomaceous earth per .thousand gallons perhours of water circulated. If greater quantities of diatomaceous earthare fed, longer runs between back-washings will be obtained, butexcessive feeds are costly, and therefore the reduction in the frequencyof back-washing must be balanced against the cost of diatomaceous earth.Changes in conditions make necessary slight changes in the feeding ofthe earth to the filter and hence it is important to have a feederPatented ct. 19, 1965 capable of fine adjustment, like that of thepresent invention.

A very compact and neat assembly is obtained by having the float box andmixing chamber of annular or doughnut design, fixed to the underside ofa table that is secured to the supporting legs for the feeder-hopper.The drive motor whose armature shafts transmits drive to the verticalshaft of the feeder is suspended Ifrom the table at the center thereofcentrally with respect to the oat box and mixing chamber and carries acooling fan on the lower end thereof driven off the armature, and theupdraft from this fan avoids over-heating of the motor on long runsdespite the enclosure thereof, while a stationary diverter barcooperating with the rotary plate and the collar that defines thedelivery slot between it and the plate directs the discharge of theearth in a steady fine stream through an opening in the table directlyinto .the mixing chamber.

The invention is illustrated in the accompanying drawings in which- FIG.1 is a central vertical section through a feeder made in accordance withour invention showing the container thereof empty and omitting theannular or doughnut shaped float box and mixing chamber and othermechanism provided below the hopper and appearing partly in sideelevation and partly in section in FIG. 2;

FIG. 2 is a similar view showing the container nearly full andindicating the mode of operation, the float box and mixing chamber beingshown in section so as to disclose the electric motor drive unit andcooling fan therefor;

FIG. 3 is a perspective view of the lower portion of FIGS. 1 and 2illustrating how the diatomaceous earth fed in calibrated amount isdischarged in a steady fine stream into the mixing chamber throughoutthe operation of the feeder;

FIG. 4 is a perspective of one form of propeller provided on the lowerend of the rotary vertical shaft in the feeder, this View serving tobetter illustrate the large chain link welded to the propeller for thedouble purpose of acting as an open or perforated paddle type mixer orstirrer, besides having the lower end of the small chain of the .feedersecured thereto, and

FIG. 5 is a piping diagram showing the hook-up of the float box andmixing chamber on the feeder with the recirculating pump for a swimmingpool filter.

The same reference numerals are applied to corresponding partsthroughout these views.

Referring to the drawings, the reference numeral 6 designates the opentop container or tank with arcuate funnel shaped bottom 7 emptying intothe upper end of a cylindrical lthroat or spout portion 8 through whichthe dry diatomaceous earth or other fine granular material indicated at9 in FIG. 2 is delivered by gravity for discharge in measured amountsthrough an annular slot 10 defined between the marginal or peripheralportion 11 of a rotary circular plate 12 and the bottom of a collar 13that is threadedly adjustable on the spout 8 and arranged to be fixedwith respect thereto in any suitable manner as by means of a set screw14. There is indicated at 15 in FIG. 3 the spilling of the earth orother granular material off the peripheral edge of the plate 12. Theturning of the plate 12 with the vertical shaft 16, cooperates in anovel manner with primary propeller 17 and a secondary propeller 18 toinsure uninterrupted delivery of the material at a steady rate, byreason of the elimination of any possibility of packing of materialeither in the throat 8 or in the container 6 at the entrance to thethroat. The primary propeller 17 operates centrally of the throat ofspout 8, and the secondary propeller 18 turns with the shaft in thehopper 6 and forms with the shaft an auger as indicated at 19 in FIG. 2when the chain forming said secondary propeller winds around the shaftto whatever height thereon, is determined by the amount of material 9left in the hopper.

The propeller 17 is in the form of an elongated U-bolt, the legs 20 ofwhich exten-d through diametrical holes 21 in the shaft 16 and have nuts22 threaded on their protruding end portions. An elongated chain link 23is welded to one leg 20 of the U-bolt 17 as indiacted at 23 in FIG. 4 in90 relationship thereto and parallel to the shaft 16 to serve as an openor perforated paddle type mixer or stirrer to cooperate with the U-bolt17 to prevent packing of mater-ial in the throat and churn or fluff thematerial just before it is discharged through the slot to spill off theperiphery 11 of the plate 12.

The propeller 18 is in the form of a heavy chain secured as indicated at24, to the outer end of a radius arm 25 xed, as indicated at 26, to theupper end portion of the shaft 16 to turn therewith, while the lower endof the chain is connected, as indicated at 27 in FIG. 1, with the upperend of a smaller chain 28 of relatively short length, the lower end ofwhich is welded or otherwise suitably secured, :as indicated at 29, tothe upper end of the paddle link 23, the length of chain 28 beingequivalent to approximately 'half the radius of the container 6, whereasthe heavy chain 18 is of a length equivalent to the height of the hopperfrom the radius arm 25 down to the -arcuate bottom 7 plus the otherihalf of the radius of said container, so that the two chains togethercan sweep the entire inside of the container and remove all materialthat might otherwise remain from the sides as well as the bottom, asshould be evident from FIG.1. The light chain 28, being secured to theshaft 16 through the medium of the link 23 in the manner shown,functions mainly to prevent plugging or packing of material at theentrance to the throat 8 without giving rise to the objection of itsdragging too much on the corner 30 dened between the upper end of thethroat 8 and bottom '7 of the container at the entrance to the throat,las such dragging would eventually result in too much wear on the chainand container.

The dry diatomaceous earth feeder, while herein illustrated inconnection with a float box and mixing chamber for production of aslurry for swimming pool filters, is not limited to such applications,as it will have many applications for the feeding of any dry powderwhether it is put into a liquid slurry or merely mixed with or added toanother dry powder or powders. That is the reason for considering theoperation of this feeder by itself iirst before describing the rest ofthe assembly.

In operation, the chain 18, being fairly heavy, tends to hang verticallyfrom the outer end of the radius arm 25 and therefore close enough tothe side wall of the container 6 to insure sweeping all materialtherefrom, and likewise from the funnel-shaped bottom 7 over which thelower end portion of chain 18 also sweeps for at least half the radiusof the container to the point of its connection 27 with the lightersmaller chain 28. The chain 28 sweeps the rest of the bottom of thecontainer to remove any remaining material therefrom. At the start,right after the container has been filled wit-h dry diatomaceous earthand the chains 18 and 28 are disposed as shown in FIG. l, the rst fewturns of the shaft 16 will automatically cause the excess portion of thelength of chains 18 and 28 to be drawn inwardly and wrap around theshaft to define the auger 19, as illustrated in FlG. 2, it being assumedthat the shaft turns in a counterclockwise direction as indicated by thearrow 31 in FIG. 2. The direction of rotation is, of course, immaterial,as the feeding of the material is the same with the shaft 16 turned ineither direction. It is due to the slack in the chains 18 and 28combined with the resistance to movement of the chains through thematerial that produces the novel operation illustrated, the Vchainswrapping around the shaft until all of the slack is taken up by theauger forming length indicated at 19 in FIG. 2. As a result of this-arrangement of the chains 18 and 28, the top of the bed is soon sweptinto a conical form, as indicated at 32 in FIG. 2, and a central passageor channel 33 is defined from the bottom of the funnel 32 down into thethroat 8 as the chains continually sweep the surfaces at 32 and 33,material being scraped actually only from the conical surface 32 by thetaut chain 18, and such material dropping down through the channel 33into the throat 8, where the open or perforated paddle type mixer 23 andpropeller 17 function together to churn and fluit the materialpreliminary to its discharge through the annular slot 1li. Obviously,the narrower this slot 10 is, the lower is the rate of ydischarge of thematerial per turn of the shaft 16, and, vice versa, if the taut angularupper portion 34 of the chain scrapes too much material for the auger 19to handle and be delivered through the throat 8 for a given setting orcalibration of the annular slot 18, resistance builds up by reason ofthe accumulation of material in the channel 33, so that the chain 18accordingly tends to wrap up tighter on the shaft 16, thereby reducingpressure of the chain at 34 on the funnel-shaped top portion 32 of thebed 9 to reduce the amount of material scraped off, and making thedevice fully automatic and self-adjusting. When some of the materialthat accumulated in channel 33 has been discharged through the slot 10,the resistance to movement of the chain relative to the material isrelieved, and the slackening chain, under the action of gravity, rubsagain on top of the bed at 32 and scrapes off more material andcontinues to do so until resistance builds up again to cause the chainto again wound la little more tightly around the shaft. This method offeeding continues until the chain is finally completely unwrapped fromthe shaft and free to assume its normal position as seen in FIG. 1 when,of course, all of the material has been cleared out of the container,and it is time to rell it. There is no perceptible variation in the rateof discharge of the material so long as there is enough material left inthe container for the chains 18 and 28 to operate upon in the mannerdescribed.

As shown in FIGS. 1-3, the container 6 is supported on three legs 35 inelevated relation to the floor 36 and these legs provide support for atable 37 below and in spaced parallel relation to the rotary plate 12mentioned above. An electric motor drive unit 38 is suspended from thecentral portion of the table 37 and carries a diametrically slottedcoupling 39 on the upper end of its armature shaft having a detachabledriving connection with the rotary vertical shaft 16` to turn it andtable 12 continuously throughout the operation of the feeder, a fan 40mounted on the lower end of the motor housing being driven off the lowerend of the armature shaft of the motor 38 to maintain an updraft of coolair past the motor throughout the period of its operation to preventover-heating thereof despite its enclosure in the central opening 41through the annular or doughnut shaped tank 42 that serves both as afloat box or tank and mixing chamber in accordance with our invention.This tank 42 is suspended from the table 37 on brackets 43 and has afloat 44 working therein, the arm thereof being pivoted to and operatinga float valve 45 suitably secured to the table 37, as indicated at 46.Water is supplied to the float valve 45 through a tube 47 connected tothe line 48, which, as will more clearly appear later, is connected onthe one hand with the discharge side of a recirculating pump 50 and onthe other hand is connected with the suction pipe 51 leading to the pumpfrom the swimming pool, whereby to maintain the necessary pressure headfor the proper functioning of an ejector 52 provided in the line 48 anddrawing water from the bottom of the tank 42 as indicated at 53, thiswater being in the form of a slurry by reason of the mixing therewith ofdiatomaceous earth 9 in a predetermined and accurately measured amountin relation to the amount of water. An opening 54 is provided in thetable 37 at a predetermined distance radially from the shaft 16 androtary plate 12 so that diatomaceous earth discharged through the slot10 between the table 12 and collar 13, when diverted by a stationary bar55 that slides on the top surface of the rotary plate 12, will bedischarged by gravity and directed in a steady fine stream through theopening 54 directly into the mixing chamber provided in the tank 42,adjacent the suction port leading into the outlet connection 53previously mentioned, this relationship being nicely illustrated in FIG.3. The bar 55 has a hollow collar 56pon its inner end that encircles theadjustable collar 13, the adjustment of which was previously describedand predetermines the rate of discharge of the diatomaceous earth, thecollar 56 having an opening 57 therein through which the earth from theslot is discharged as shown in FIG. 3 and, due to the angularity of thebar 55 with respect to a radius of the plate 12, the bar 55 beingsubstantially tangential with respect to the collar S6, the diatomaceousearth is automatically discharged along the bar off the periphery of theplate 12 and drops by gravity through the opening 54, a vertical pin 58in the table 37 forming an abutment for the outer end of the bar 55 tohold it against turning with the plate 12.

A rate-setting plug valve 59 in the line 4S is accurately adjusted topredetermine the rate of flow of water through the ejector 52 to entrainslurry from connection 53. Hand-operable gate valves are provided at 60and 61 in the line 48 on opposite sides of the rate-set plug valve 59,and a check valve 62 is provided in the line near the suction pipe 51only when the feeder is installed below the pool level, to prevent waterfrom the pool backing up into the feeder. The level in the mixingchamber in tank 42 is maintained at a certain elevation by adjusting therate-set plug 59. If the water level rises above the desired elevation,the rate-set plug 59 is opened slightly. On the other hand, if the leveldrops below a predetermined elevation, the rate-set plug 59 is closedslightly.

It is believed the foregoing description conveys a good understanding ofthe objects and advantages of our invention. The appended claims havebeen drawn to cover all legitimate modifications and adaptations.

i We claim:

1. In a device of the character described, the combination of an uprightsubstantially cylindrical container having a funnel-shaped bottomportion with a discharge neck at the center thereof, a vertical shaftextending centrally through said container, a radius arm on the upperend portion of said shaft, a fiexible sweeper element connected to andarranged to extend downwardly from the outer end of said radius arm,when free to do so by gravity, inside said container in close proximityto the side wall to the bottom of said container and inwardly across andin contact with the hopper bottom and connected at its lower end to saidshaft, and means for turning said shaft, said flexible sweeper elementbeing adapted when the container contains a bed of granular material towind its excess length around said shaft in the form of a helix of avariable length, measured from the lower end of said shaft,substantially equal to the depth of the bed, the wound lengthcooperating with the shaft to act as an auger to form a verticalsubstantially cylindrical channel in said bed at the center thereofconcentric with said shaft while the upper end portion of said elementextending radially to the outer end of said radius arm defines agenerally conical depression in the upper end of said bed serving tosweep material therefrom to ow by gravity downwardly through theaforesaid channel for discharge at a steady, substantially uniform ratefrom said neck.

2. The combination as set forth in claim 1 including a substantiallyradial open projection on said shaft inside the neck for agitation ofthe material finding its way into said neck, whereby to prevent packingof the material in said neck and maintain a substantially steady anduniform iiow of such material through said neck.

3. The combination as set forth in claim 1 including a substantiallyradial open projection on said shaft inside the neck for agitation ofthe material finding its way into said neck, whereby to prevent packingof the material in said neck and maintain a substantially steady anduniform ow of such material through said neck, the lower end of theflexible sweeper element being connected to said shaft by means of saidprojection.

4. The combination as set forth in claim 1 including a substantiallyradial open projection on said shaft inside the neck for agitation ofthe material nding its way into said neck, whereby to prevent packing ofthe material in said neck and maintain a substantially steady anduniform flow of such material through said neck, there being anotheropen projection in xed relationship to the first mentioned projectionand extending upwardly therefrom in radially spaced relationship to saidshaft intermediate the ends of said rst projection, said secondprojection reaching the upper region in said neck to further reduce anylikelihood of packing of the material in said neck.

5. The combination as set forth in claim 1 including a substantiallyradial open projection on said shaft inside the neck for agitation ofthe material finding its way into said neck, whereby to prevent packingof the material in said neck and maintain a substantially steady anduniform flow of such material through said neck, there being anotheropen projection in fixed relationship to the first mentioned projectionand extending upwardly therefrom in radially spaced relationship to saidshaft intermediate the ends of said first projection, said secondprojection reaching the upper region in said neck to further reduce anylikelihood of packing of the material in said neck, the lower end ofsaid fiexible sweeper element being connected with said shaft by meansof said last mentioned projection.

6. The combination as set forth in claim 1 wherein the flexible sweeperelement comprises a chain.

7. The combination as set forth in claim 1 wherein the flexible sweeperelement comprises a chain, the major length of which is a relativelyheavy chain reaching from the outer end of said radius arm downwardly tothe bottom of said container and inwardly across at least a portion ofthe radius of the hopper bottom, there being another appreciably lighterchain connected with and extending from the lower end of the first chainto the point of connection with said shaft in said neck, whereby toreduce wear on the container at the junction of the neck and hopperbottom.

8. The combination as set forth in claim 1 wherein the flexible sweeperelement comprises a chain, the major length of which is a relativelyheavy chain reaching from the outer end of said radius arm downwardly tothe bottom of said container and inwardly across at least a portion ofthe radius of the hopper bottom, there being another appreciably lighterchain connected with and extending from the lower end of the first chainto the point of connection with said shaft in said neck, whereby toreduce wear on the container at the junction of the neck and hopperbottom, the device including a generally U- shaped stirrer element rigidwith said shaft and extending radially therefrom in a substantiallyvertical plane inside said neck and at an elevation intermediate theends of the latter, the lower end of the lighter chain being connectedto said shaft by means of said U-shaped element.

9. The combination as set forth in claim 1 wherein the flexible sweeperelement comprises a chain, the major length of which is a relativelyheavy chain reaching from the outer end of said radius arm downwardly tothe bottom of said container and inwardly across at least a portion ofthe radius of the hopper bottom, there being another appreciably lighterchain connected with and extending from the lower end of the first chainto the point of connection with said shaft in said neck, whereby toreduce wear on the container at the junction of the neck and hopperbottom, the device including a generally U- shaped stirrer element rigidwith said shaft and extending radially therefrom in a substantiallyvertical plane inside said neck and at an elevation intermediate theends of the latter, and another stirrer element in the form of asubstantially vertical loop rigid with the upper portion of saidU-shaped element intermediate the ends thereof and having the lower endof the lighter chain connected to said shaft by means of said loop.

10. In a device of the character described, the combination of anupright substantially cylindrical container having a funnel-shapedbottom portion with a discharge neck at the center thereof, a verticalshaft extending centrally through said container and down through saidneck and supported for rotation, means for turning said shaft, means onsaid shaft which in the turning thereof dislodges material stored in thecontainer about said shaft for discharge through said neck, asubstantially horizontal plate turning with said shaft in closely spacedrelation to the lower end of said neck to dene with the latter anannular discharge orifice, a first collar adjustable axially on and withrespect to said neck and relative to said plate to vary the width ofsaid annular orifice and thereby regulate the rate of discharge of thematerial, a second collar surrounding the lower end portion of the firstcollar and resting on said plate, said second collar having a lateraldischarge opening, and a scraper arm rigid with and extending from saidsecond collar to direct the material discharged from said opening in astream from the periphery of said plate.

11. In a device of the character described, the combination of anupright substantially cylindrical container having a funnel-shapedbottom portion with a discharge neck at the center thereof, a verticalshaft extending centrally through said container and down through saidneck and supported for rotation, means for turning said shaft, means onsaid shaft which in the turning thereof dislodges material stored in thecontainer about said shaft for discharge through said neck, asubstantially horizontal plate turning with said shaft in closely spacedrelation to the lower end of said neck to define with the latter anannular discharge orifice, a rst collar adjustable axially on and withrespect to said neck and relative to said plate to vary the width ofsaid annular orice and thereby regulate the rate of discharge of thematerial, a second collar surrounding the lower end portion of the firstcollar and resting on said plate, said second collar having a lateraldischarge opening, a scraper arm rigid with and extending from saidsecond collar to direct the material discharged from said opening in astream from the periphery of said plate, and a mixing chamber disposedbelow the discharge point of said plate to receive the stream ofmaterial discharged and dropping by gravity from the periphery of saidplate, said chamber having other material delivered thereto for mixingwith the lirst mentioned material, the mixture so formed being thendischarged from said chamber.

12. In a device of the character described, the combination of anupright substantially cylindrical container having a funnel-shapedbottom portion with a discharge neck at the center thereof, a verticalshaft extending centrally through said container and down through saidneck and supported for rotation, means for turning said shaft, means onsaid shaft which in the turning thereof dislodges material stored in thecontainer about said shaft for discharge through said neck, asubstantially horizontal plate turning with said shaft in closely spacedrelation to the lower end Iof said neck to dene with the latter anannular discharge orifice, means directing the material from said plateto drop in a single stream from the periphery of said plate, asubstantially horizontal support mounted below and in a fixed spacedrelationship of to said plate and having an opening provided thereinthrough which the stream of material is discharged by gravitydownwardly, an open top ring-shaped container for liquid suspended fromsaid support in a position to receive the stream of material into amixing chamber in one portion thereof for mixing with liquid therein,means for delivering liquid to the mxing chamber in said ring-shapedcontaner, means for withdrawing from the mixing chamber, the slurryformed by the mixing of the material with the liquid in said container,and an electric motor suspended from said support in the space in thecentral portion of said ring-shaped container and having a drivingconnection with the lower end of the aforesaid shaft.

13. A device as set forth in claim 12, including a fan driven by saidmotor and operating therebeneath in the same space with the motor tocirculate air upwardly past the motor and out between the ring-shapedtank and the bottom of said support.

14. A device as set forth in claim 12, including a float and floatoperated valve connected to said liquid delivering means for controllingthe delivery of liquid to said ring-shaped container, whereby tomaintain a predetermined level of liquid therein.

15. In a device of the character described, the combination of anupright substantially cylindrical container having a funnel-shapedbottom portion with a discharge neck at the center thereof, a verticalshaft extending centrally through said container and down through saidneck and supported for rotation, means for turning said shaft, means onsaid shaft which in the turning thereof dislodges material stored in thecontainer about said shaft for discharge through said neck, asubstantially horizontal plate turning with said shaft in closely spacedrelation to the lower end of said neck to define with the latter anannular discharge orifice, a first collar adjustable axially on and withrespect to said neck and relative to said plate to vary the width ofsaid annular orifice and thereby regulate the rate of discharge of thematerial, a second collar surrounding the lower end portion of the firstcollar and resting on said plate, said second collar having a lateraldischarge opening, a scraper arm rigid with and extending from saidsecond collar to direct the material discharged from said opening in astream from the periphery of said plate, a substantially horizontalsupport mounted below and in a fixed spaced relationship to said plateand having an opening provided therein through which the stream ofmaterial is discharged by gravity downwardly, an open top ring-shapedcontainer for liquid suspended from said support in a position toreceive the stream of material into a mixing chamber in one portionthereof for mixing with liquid therein, means for delivering liquid tothe mixing chamber in said ring-shaped container, means for withdrawingfrom the mixing chamber the slurry formed by the mixing of the materialwith the liquid in said container, and an electric motor suspended fromsaid support in the space in the central portionof said ring-shapedcontainer and having a driving connection with the lower end of theaforesaid shaft, said support having a lstop projection provided thereonextending upwardly therefrom alongside the periphery of said plate, andthe scraper arm abutting said stop projection to prevent turning of thesecond collar with said plate.

References Cited by the Examiner UNITED STATES PATENTS 55,872 6/ 66Hutchinson 222-285 X 469,370 2/92 Cutts 222-406 yX 636,370 11/99 Wetmore222-56 X 1,543,915 6/25 Green 222-228 2,228,421 1/41 Taylor 222-406 X2,533,852 12/50 Tietig 222-56 X 2,569,486 10/51 Mills.

2,934,037 4/60 Ernest 222-406 X 3,037,713 6/ 62 Carroll 222-228 XFOREIGN PATENTS 1,083,207 l/55 France. 1,146,448 ll/57 France.

LOUIS J. DEMBO, Primary Examiner.

12. IN A DEVICE OF THE CHARACTER DESCRIBED, THE COMBINATION OF ANUPRIGHT SUBSTANTIALLY CYLINDRICAL CONTAINER HAVING A FUNNEL-SHAPEDBOTTOM PORTION WITH A DISCHARGE NECK AT THE CENTER THEREOF, A VERTICALSHAFT EXTENDING CENTRALLY THROUGH SAID CONTAINER AND DOWN THROUGH SAIDNECK AND SUPPORTED FOR ROTATION, MEANS FOR TURNING SAID SHAFT, MEANS ONSAID SHAFT WHICH IN THE TURNING THEREOF DISLODGES MATERIAL STORED IN THECONTAINER ABOUT SAID SHAFT FOR DISCHARGE THROUGH SAID NECK, ASUBSTANTIALLY HORIZONTAL PLATE TURNING WITH SAID SHAFT IN CLOSELY SPACEDRELATION TO THE LOWER END OF SAID NECK TO DEFINE WITH THE LATTER ANANNULAR DISCHARGE ORIFICE, MEANS DIRECTING THE MATERIAL FROM SAID PLATETO DROP IN A SINGLE STREAM FROM THE PERIPHERY OF SAID PLATE, ASUBSTANTIALLY HORIZONIAL SUPPORT MOUNTED BELOW AND IN A FIXED SPACEDRELATIONSHIP OF TO SAID PLATE AND HAVING AN OPENING PROVIDED THEREINTHROUGH WHICH THE STREAM OF MATERIAL IS DISCHARGED BY GRAVITYDOWNWARDLY, AN OPEN TOP RING-SHAPED CONTAINER FOR LIQUID SUSPENDED FROMSAID SUPPORT IN A POSITION TO RECEIVE THE STREAM OF MATERIAL INTO AMIXING CHAMBER IN ONE PORTION THEREOF THE MIXING WITH LIQUID THEREIN,MEANS FOR DELIVERING LIQUID TO THE MIXING CHAMBER IN SAID RING-SHAPEDCONTAINER, MEANS FOR WITHDRAWING FROM THE MIXING CHAMBER, THE SLURRYFORMED BY THE MIXING OF THE MATERIAL WITH THE LIQUID IN SAID CONTAINER,AND AN ELECTRIC MOTOR SUSPENDED FROM SAID SUPPORT IN THE SPACE IN THECENTRAL PORTION OF SAID RING-SHAPED CONTAINER AND HAVING A DRIVINGCONNECTION WITH THE LOWER END OF THE AFORESAID SHAFT.